Method and apparatus for transmitting/receiving wireless signal in wireless communication system

ABSTRACT

According to an embodiment of the present invention, a user equipment (UE) may receive one or more physical downlink control channels (PDCCHs) each carrying downlink control information (DCI) including a field indicating a transmitting configuration index (TCI) state, and receive, based the one or more PDCCHs, one or more of a plurality of physical downlink shared channels (PDSCHs), wherein the plurality of PDSCHs may carry a same transport block (TB) in a plurality of TCI states, respectively, and the UE can determine, for each TCI state, whether a hybrid automatic repeat request (HARQ) operation is enabled or disabled, and transmits HARQ-acknowledgement (ACK) information for the same TB through a physical uplink control channel (PUCCH) associated with an HARQ operation-enabled TCI state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of KR patent Applications No.10-2020-0138026 filed on Oct. 23, 2020 and No. 10-2020-0138028 filed onOct. 23, 2020 which are hereby incorporated by reference as if fully setforth herein.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system, andmore particularly, to a method and apparatus for transmitting/receivinga wireless signal.

BACKGROUND

Generally, a wireless communication system is developing to diverselycover a wide range to provide such a communication service as an audiocommunication service, a data communication service and the like. Thewireless communication is a sort of a multiple access system capable ofsupporting communications with multiple users by sharing availablesystem resources (e.g., bandwidth, transmit power, etc.). For example,the multiple access system may be any of a code division multiple access(CDMA) system, a frequency division multiple access (FDMA) system, atime division multiple access (TDMA) system, an orthogonal frequencydivision multiple access (OFDMA) system, and a single carrier frequencydivision multiple access (SC-FDMA) system.

SUMMARY

An object of the present disclosure is to provide a method ofefficiently performing wireless signal transmission/reception proceduresand an apparatus therefor.

It will be appreciated by persons skilled in the art that the objectsand advantages that could be achieved with the present disclosure arenot limited to what has been particularly described hereinabove and theabove and other objects and advantages that the present disclosure couldachieve will be more clearly understood from the following detaileddescription.

In an aspect of the present invention, a method of receiving a signal bya user equipment (UE) in a wireless communication system, may comprisesreceiving one or more physical downlink control channels (PDCCHs) eachcarrying downlink control information (DCI) including a field indicatinga transmitting configuration index (TCI) state; and receiving, based theone or more PDCCHs, one or more of a plurality of physical downlinkshared channels (PDSCHs). The plurality of PDSCHs can be configured tocarry a same transport block (TB) in a plurality of TCI states,respectively. The UE may determine, for each TCI state, whether a hybridautomatic repeat request (HARQ) operation is enabled or disabled, andtransmit HARQ-acknowledgement (ACK) information for the same TB througha physical uplink control channel (PUCCH) associated with an HARQoperation-enabled TCI state.

The plurality of PDSCHs may be related to different TCI states,respectively.

Each DCI of each PDCCH may include information indicating whether theHARQ operation is enabled or disabled for a corresponding TCI state.

A PUCCH transmit power control (TPC) command may be omitted incorresponding DCI which disables the HARQ operation for a correspondingTCI state.

The UE may obtain the PUCCH TPC command only from HARQ operationenabling-DCI.

The DCI in each PDCCH may schedule each PDSCH.

A resource of the PUCCH can be indicated by corresponding DCI associatedwith the HARQ operation-enabled TCI state.

The one or more PDSCHs received by the UE can be selected from among theplurality of the PDSCHs, based on each reference signal measurementperformed for each TCI state.

The UE may perform one or more PUCCH transmissions related to the sameTB reception, based on each reference signal measurement performed foreach TCI state.

The same TB carried by the plurality of the PDSCHs may be related to amulticast broadcast service (MBS). The DCI may be common for a group ofUEs receiving the MBS.

According to other aspect of the present invention, a non-transitorycomputer readable medium recorded thereon program codes for performingthe aforementioned method is presented.

According to another aspect of the present invention, the UE configuredto perform the aforementioned method is presented.

According to another aspect of the present invention, a deviceconfigured to control the UE to perform the aforementioned method ispresented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates physical channels used in a 3rd generationpartnership project (3GPP) system, which is an example of wirelesscommunication systems, and a general signal transmission method usingthe same;

FIG. 2 illustrates a radio frame structure;

FIG. 3 illustrates a resource grid of a slot;

FIG. 4 illustrates exemplary mapping of physical channels in a slot;

FIG. 5 is a diagram illustrating a signal flow for a physical downlinkcontrol channel (PDCCH) transmission and reception process;

FIG. 6 illustrates an ACK/NACK transmission example.

FIG. 7 illustrates a PUSCH transmission example

FIG. 8 to FIG. 12 illustrates various examples of PDSCH transmission andretransmissions according to an embodiment of the present invention;

FIG. 13 illustrates a method of receiving a signal by a user equipmentin an embodiment of the present invention;

FIG. 14 to FIG. 17 illustrate a communication system 1 and wirelessdevices applied to the present disclosure; and

FIG. 18 illustrates an exemplary discontinuous reception (DRX) operationapplied to the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are applicable to a variety ofwireless access technologies such as code division multiple access(CDMA), frequency division multiple access (FDMA), time divisionmultiple access (TDMA), orthogonal frequency division multiple access(OFDMA), and single carrier frequency division multiple access(SC-FDMA). CDMA can be implemented as a radio technology such asUniversal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can beimplemented as a radio technology such as Global System for Mobilecommunications (GSM)/General Packet Radio Service (GPRS)/Enhanced DataRates for GSM Evolution (EDGE). OFDMA can be implemented as a radiotechnology such as Institute of Electrical and Electronics Engineers(IEEE) 802.11 (Wireless Fidelity (Wi-Fi)), IEEE 802.16 (Worldwideinteroperability for Microwave Access (WiMAX)), IEEE 802.20, and EvolvedUTRA (E-UTRA). UTRA is a part of Universal Mobile TelecommunicationsSystem (UMTS). 3rd Generation Partnership Project (3GPP) Long TermEvolution (LTE) is part of Evolved UMTS (E-UMTS) using E-UTRA, andLTE-Advanced (A) is an evolved version of 3GPP LTE. 3GPP NR (New Radioor New Radio Access Technology) is an evolved version of 3GPP LTE/LTE-A.

As more and more communication devices require a larger communicationcapacity, there is a need for mobile broadband communication enhancedover conventional radio access technology (RAT). In addition, massiveMachine Type Communications (MTC) capable of providing a variety ofservices anywhere and anytime by connecting multiple devices and objectsis another important issue to be considered for next generationcommunications. Communication system design considering services/UEssensitive to reliability and latency is also under discussion. As such,introduction of new radio access technology considering enhanced mobilebroadband communication (eMBB), massive MTC, and Ultra-Reliable and LowLatency Communication (URLLC) is being discussed. In the presentdisclosure, for simplicity, this technology will be referred to as NR(New Radio or New RAT).

For the sake of clarity, 3GPP NR is mainly described, but the technicalidea of the present disclosure is not limited thereto.

Details of the background, terminology, abbreviations, etc. used hereinmay be found in 3GPP standard documents published before the presentdisclosure.

Following documents are incorporated by reference:

3GPP LTE

-   -   TS 36.211: Physical channels and modulation    -   TS 36.212: Multiplexing and channel coding    -   TS 36.213: Physical layer procedures    -   TS 36.300: Overall description    -   TS 36.321: Medium Access Control (MAC)    -   TS 36.331: Radio Resource Control (RRC)

3GPP NR

-   -   TS 38.211: Physical channels and modulation    -   TS 38.212: Multiplexing and channel coding    -   TS 38.213: Physical layer procedures for control    -   TS 38.214: Physical layer procedures for data    -   TS 38.300: NR and NG-RAN Overall Description    -   TS 38.321: Medium Access Control (MAC)    -   TS 38.331: Radio Resource Control (RRC) protocol specification

ABBREVIATIONS AND TERMS

-   -   PDCCH: Physical Downlink Control CHannel    -   PDSCH: Physical Downlink Shared CHannel    -   PUSCH: Physical Uplink Shared CHannel    -   CSI: Channel state information    -   RRM: Radio resource management    -   RLM: Radio link monitoring    -   DCI: Downlink Control Information    -   CAP: Channel Access Procedure    -   Ucell: Unlicensed cell    -   PCell: Primary Cell    -   PSCell: Primary SCG Cell    -   TBS: Transport Block Size    -   SLIV: Starting and Length Indicator Value    -   BWP: BandWidth Part    -   CORESET: COntrol REsourse SET    -   REG: Resource element group    -   SFL: Slot Format Indicator    -   COT: Channel occupancy time    -   SPS: Semi-persistent scheduling    -   PLMN ID: Public Land Mobile Network identifier    -   RACH: Random Access Channel    -   RAR: Random Access Response    -   Msg3: Message transmitted on UL-SCH containing a C-RNTI MAC CE        or CCCH SDU, submitted from upper layer and associated with the        UE Contention Resolution Identity, as part of a Random Access        procedure.    -   Special Cell: For Dual Connectivity operation the term Special        Cell refers to the PCell of the MCG or the PSCell of the SCG        depending on if the MAC entity is associated to the MCG or the        SCG, respectively. Otherwise the term Special Cell refers to the        PCell. A Special Cell supports PUCCH transmission and        contention-based Random Access, and is always activated.    -   Serving Cell: A PCell, a PSCell, or an SCell

In a wireless communication system, a user equipment (UE) receivesinformation through downlink (DL) from a base station (BS) and transmitinformation to the BS through uplink (UL). The information transmittedand received by the BS and the UE includes data and various controlinformation and includes various physical channels according totype/usage of the information transmitted and received by the UE and theBS.

FIG. 1 illustrates physical channels used in a 3GPP NR system and ageneral signal transmission method using the same.

When a UE is powered on again from a power-off state or enters a newcell, the UE performs an initial cell search procedure, such asestablishment of synchronization with a BS, in step 5101. To this end,the UE receives a synchronization signal block (SSB) from the BS. TheSSB includes a primary synchronization signal (PSS), a secondarysynchronization signal (SSS), and a physical broadcast channel (PBCH).The UE establishes synchronization with the BS based on the PSS/SSS andacquires information such as a cell identity (ID). The UE may acquirebroadcast information in a cell based on the PBCH. The UE may receive aDL reference signal (RS) in an initial cell search procedure to monitora DL channel status.

After initial cell search, the UE may acquire more specific systeminformation by receiving a physical downlink control channel (PDCCH) andreceiving a physical downlink shared channel (PDSCH) based oninformation of the PDCCH in step S102.

The UE may perform a random access procedure to access the BS in stepsS103 to S106. For random access, the UE may transmit a preamble to theBS on a physical random access channel (PRACH) (S103) and receive aresponse message for preamble on a PDCCH and a PDSCH corresponding tothe PDCCH (S104). In the case of contention-based random access, the UEmay perform a contention resolution procedure by further transmittingthe PRACH (S105) and receiving a PDCCH and a PDSCH corresponding to thePDCCH (S106).

After the foregoing procedure, the UE may receive a PDCCH/PDSCH (S107)and transmit a physical uplink shared channel (PUSCH)/physical uplinkcontrol channel (PUCCH) (S108), as a general downlink/uplink signaltransmission procedure. Control information transmitted from the UE tothe BS is referred to as uplink control information (UCI). The UCIincludes hybrid automatic repeat and requestacknowledgement/negative-acknowledgement (HARQ-ACK/NACK), schedulingrequest (SR), channel state information (CSI), etc. The CSI includes achannel quality indicator (CQI), a precoding matrix indicator (PMI), arank indicator (RI), etc. While the UCI is transmitted on a PUCCH ingeneral, the UCI may be transmitted on a PUSCH when control informationand traffic data need to be simultaneously transmitted. In addition, theUCI may be aperiodically transmitted through a PUSCH according torequest/command of a network.

FIG. 2 illustrates a radio frame structure. In NR, uplink and downlinktransmissions are configured with frames. Each radio frame has a lengthof 10 ms and is divided into two 5-ms half-frames (HF). Each half-frameis divided into five 1-ms subframes (SFs). A subframe is divided intoone or more slots, and the number of slots in a subframe depends onsubcarrier spacing (SCS). Each slot includes 12 or 14 OrthogonalFrequency Division Multiplexing (OFDM) symbols according to a cyclicprefix (CP). When a normal CP is used, each slot includes 14 OFDMsymbols. When an extended CP is used, each slot includes 12 OFDMsymbols.

Table 1 exemplarily shows that the number of symbols per slot, thenumber of slots per frame, and the number of slots per subframe varyaccording to the SCS when the normal CP is used.

TABLE 1 SCS (15*2 ^(u)) N ^(slot) _(symb) N ^(frame, u) _(slot) N^(subframe, u) _(slot)  15 KHz (u = 0) 14 10 1  30 KHz (u = 1) 14 20 2 60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4) 14 16016 * N ^(slot) _(symb): Number of symbols in a slot * N ^(frame, u)_(slot): Number of slots in a frame * N ^(subframe, u) _(slot): Numberof slots in a subframe

Table 2 illustrates that the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe vary according tothe SCS when the extended CP is used.

TABLE 2 SCS (15*2 ^(u)) N ^(slot) _(symb) N ^(frame, u) _(slot) N^(subframe, u) _(slot) 60 KHz (u = 2) 12 40 4

The structure of the frame is merely an example. The number ofsubframes, the number of slots, and the number of symbols in a frame mayvary.

In the NR system, OFDM numerology (e.g., SCS) may be configureddifferently for a plurality of cells aggregated for one UE. Accordingly,the (absolute time) duration of a time resource (e.g., an SF, a slot ora TTI) (for simplicity, referred to as a time unit (TU)) consisting ofthe same number of symbols may be configured differently among theaggregated cells. Here, the symbols may include an OFDM symbol (or aCP-OFDM symbol) and an SC-FDMA symbol (or a discrete Fouriertransform-spread-OFDM (DFT-s-OFDM) symbol).

FIG. 3 illustrates a resource grid of a slot. A slot includes aplurality of symbols in the time domain. For example, when the normal CPis used, the slot includes 14 symbols. However, when the extended CP isused, the slot includes 12 symbols. A carrier includes a plurality ofsubcarriers in the frequency domain. A resource block (RB) is defined asa plurality of consecutive subcarriers (e.g., 12 consecutivesubcarriers) in the frequency domain. A bandwidth part (BWP) may bedefined to be a plurality of consecutive physical RBs (PRBs) in thefrequency domain and correspond to a single numerology (e.g., SCS, CPlength, etc.). The carrier may include up to N (e.g., 5) BWPs. Datacommunication may be performed through an activated BWP, and only oneBWP may be activated for one UE. In the resource grid, each element isreferred to as a resource element (RE), and one complex symbol may bemapped to each RE.

FIG. 4 illustrates exemplary mapping of physical channels in a slot. Inthe NR system, a frame is characterized by a self-contained structure inwhich all of a DL control channel, DL or UL data, and a UL controlchannel may be included in one slot. For example, the first N symbols(hereinafter, referred to as a DL control region) of a slot may be usedto transmit a DL control channel (e.g., PDCCH), and the last M symbols(hereinafter, referred to as a UL control region) of the slot may beused to transmit a UL control channel (e.g., PUCCH). Each of N and M isan integer equal to or larger than 0. A resource region (hereinafter,referred to as a data region) between the DL control region and the ULcontrol region may be used to transmit DL data (e.g., PDSCH) or UL data(e.g., PUSCH). A guard period (GP) provides a time gap for transmissionmode-to-reception mode switching or reception mode-to-transmission modeswitching at a BS and a UE. Some symbol at the time of DL-to-ULswitching in a subframe may be configured as a GP.

The PDCCH delivers DCI. For example, the PDCCH (i.e., DCI) may carryinformation about a transport format and resource allocation of a DLshared channel (DL-SCH), resource allocation information of an uplinkshared channel (UL-SCH), paging information on a paging channel (PCH),system information on the DL-SCH, information on resource allocation ofa higher-layer control message such as an RAR transmitted on a PDSCH, atransmit power control command, information about activation/release ofconfigured scheduling, and so on. The DCI includes a cyclic redundancycheck (CRC). The CRC is masked with various identifiers (IDs) (e.g. aradio network temporary identifier (RNTI)) according to an owner orusage of the PDCCH. For example, if the PDCCH is for a specific UE, theCRC is masked by a UE ID (e.g., cell-RNTI (C-RNTI)). If the PDCCH is fora paging message, the CRC is masked by a paging-RNTI (P-RNTI). If thePDCCH is for system information (e.g., a system information block(SIB)), the CRC is masked by a system information RNTI (SI-RNTI). Whenthe PDCCH is for an RAR, the CRC is masked by a random access-RNTI(RA-RNTI).

FIG. 5 is a diagram illustrating a signal flow for a PDCCH transmissionand reception process.

Referring to FIG. 5, a BS may transmit a control resource set (CORESET)configuration to a UE (S502). A CORSET is defined as a resource elementgroup (REG) set having a given numerology (e.g., an SCS, a CP length,and so on). An REG is defined as one OFDM symbol by one (P)RB. Aplurality of CORESETs for one UE may overlap with each other in thetime/frequency domain. A CORSET may be configured by system information(e.g., a master information block (MIB)) or higher-layer signaling(e.g., radio resource control (RRC) signaling). For example,configuration information about a specific common CORSET (e.g., CORESET#0) may be transmitted in an MIB. For example, a PDSCH carrying systeminformation block 1 (SIB1) may be scheduled by a specific PDCCH, andCORSET #0 may be used to carry the specific PDCCH. Configurationinformation about CORESET #N (e.g., N>0) may be transmitted by RRCsignaling (e.g., cell-common RRC signaling or UE-specific RRCsignaling). For example, the UE-specific RRC signaling carrying theCORSET configuration information may include various types of signalingsuch as an RRC setup message, an RRC reconfiguration message, and/or BWPconfiguration information. Specifically, a CORSET configuration mayinclude the following information/fields.

-   -   controlResourceSetId: indicates the ID of a CORESET.    -   frequencyDomainResources: indicates the frequency resources of        the CORESET. The frequency resources of the CORESET are        indicated by a bitmap in which each bit corresponds to an RBG        (e.g., six (consecutive) RBs). For example, the most significant        bit (MSB) of the bitmap corresponds to a first RBG. RBGs        corresponding to bits set to 1 are allocated as the frequency        resources of the CORESET.    -   duration: indicates the time resources of the CORESET. Duration        indicates the number of consecutive OFDM symbols included in the        CORESET. Duration has a value of 1 to 3.    -   cce-REG-MappingType: indicates a control channel element        (CCE)-REG mapping type. Interleaved and non-interleaved types        are supported.    -   interleaverSize: indicates an interleaver size.    -   pdcch-DMRS-ScramblingID: indicates a value used for PDCCH DMRS        initialization. When pdcch-DMRS-ScramblingID is not included,        the physical cell ID of a serving cell is used.    -   precoderGranularity: indicates a precoder granularity in the        frequency domain.    -   reg-BundleSize: indicates an REG bundle size.    -   tci-PresentInDCI: indicates whether a transmission configuration        index (TCI) field is included in DL-related DCI.    -   tci-StatesPDCCH-ToAddList: indicates a subset of TCI states        configured in pdcch-Config, used for providing quasi-co-location        (QCL) relationships between DL RS(s) in an RS set (TCI-State)        and PDCCH DMRS ports.

Further, the BS may transmit a PDCCH search space (SS) configuration tothe UE (S504). The PDCCH SS configuration may be transmitted byhigher-layer signaling (e.g., RRC signaling). For example, the RRCsignaling may include, but not limited to, various types of signalingsuch as an RRC setup message, an RRC reconfiguration message, and/or BWPconfiguration information. While a CORESET configuration and a PDCCH SSconfiguration are shown in FIG. 5 as separately signaled, forconvenience of description, the present disclosure is not limitedthereto. For example, the CORESET configuration and the PDCCH SSconfiguration may be transmitted in one message (e.g., by one RRCsignaling) or separately in different messages.

The PDCCH SS configuration may include information about theconfiguration of a PDCCH SS set. The PDCCH SS set may be defined as aset of PDCCH candidates monitored (e.g., blind-detected) by the UE. Oneor more SS sets may be configured for the UE. Each SS set may be a USSset or a CSS set. For convenience, PDCCH SS set may be referred to as“SS” or “PDCCH SS”.

A PDCCH SS set includes PDCCH candidates. A PDCCH candidate is CCE(s)that the UE monitors to receive/detect a PDCCH. The monitoring includesblind decoding (BD) of PDCCH candidates. One PDCCH (candidate) includes1, 2, 4, 8, or 16 CCEs according to an aggregation level (AL). One CCEincludes 6 REGs. Each CORESET configuration is associated with one ormore SSs, and each SS is associated with one CORESET configuration. OneSS is defined based on one SS configuration, and the SS configurationmay include the following information/fields.

-   -   searchSpaceId: indicates the ID of an SS.    -   controlResourceSetId: indicates a CORESET associated with the        SS.    -   monitoringSlotPeriodicityAndOffset: indicates a periodicity (in        slots) and offset (in slots) for PDCCH monitoring.    -   monitoringSymbolsWithinSlot: indicates the first OFDM symbol(s)        for PDCCH monitoring in a slot configured with PDCCH monitoring.        The first OFDM symbol(s) for PDCCH monitoring is indicated by a        bitmap with each bit corresponding to an OFDM symbol in the        slot. The MSB of the bitmap corresponds to the first OFDM symbol        of the slot. OFDM symbol(s) corresponding to bit(s) set to 1        corresponds to the first symbol(s) of a CORESET in the slot.    -   nrofCandidates: indicates the number of PDCCH candidates (one of        values 0, 1, 2, 3, 4, 5, 6, and 8) for each AL where AL={ 1, 2,        4, 8, 16}.    -   searchSpaceType: indicates common search space (CSS) or        UE-specific search space (USS) as well as a DCI format used in        the corresponding SS type.

Subsequently, the BS may generate a PDCCH and transmit the PDCCH to theUE (S506), and the UE may monitor PDCCH candidates in one or more SSs toreceive/detect the PDCCH (S508). An occasion (e.g., time/frequencyresources) in which the UE is to monitor PDCCH candidates is defined asa PDCCH (monitoring) occasion. One or more PDCCH (monitoring) occasionsmay be configured in a slot.

Table 3 shows the characteristics of each SS.

TABLE 3 Search Type Space RNTI Use Case Type0- Common SI-RNTI on aprimary cell SIB PDCCH Decoding Type0A- Common SI-RNTI on a primary cellSIB PDCCH Decoding Type1- Common RA-RNTI or TC-RNTI on a primary Msg2,PDCCH cell Msg4 decoding in RACH Type2- Common P-RNTI on a primary cellPaging PDCCH Decoding Type3- Common INT-RNTI, SFI-RNTI, TPC-PUSCH- PDCCHRNTI, TPC-PUCCH-RNTI, TPC-SRS- RNTI, C-RNTI, MCS-C-RNTI, or CS- RNTI(s)UE C-RNTI, or MCS-C-RNTI, or CS- User Specific RNTI(s) specific PDSCHdecoding

Table 4 shows DCI formats transmitted on the PDCCH.

TABLE 4 DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s)where UE may assume no transmission is intended for the UE 2_2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs

DCI format 0_0 may be used to schedule a TB-based (or TB-level) PUSCH,and DCI format 0_1 may be used to schedule a TB-based (or TB-level)PUSCH or a code block group (CBG)-based (or CBG-level) PUSCH. DCI format1_0 may be used to schedule a TB-based (or TB-level) PDSCH, and DCIformat 1_1 may be used to schedule a TB-based (or TB-level) PDSCH or aCBG-based (or CBG-level) PDSCH (DL grant DCI). DCI format 0_0/0_1 may bereferred to as UL grant DCI or UL scheduling information, and DCI format1_0/1_1 may be referred to as DL grant DCI or DL scheduling information.DCI format 2_0 is used to deliver dynamic slot format information (e.g.,a dynamic slot format indicator (SFI)) to a UE, and DCI format 2_1 isused to deliver DL pre-emption information to a UE. DCI format 2_0and/or DCI format 2_1 may be delivered to a corresponding group of UEson a group common PDCCH which is a PDCCH directed to a group of UEs.

DCI format 0_0 and DCI format 1_0 may be referred to as fallback DCIformats, whereas DCI format 0_1 and DCI format 1_1 may be referred to asnon-fallback DCI formats. In the fallback DCI formats, a DCI size/fieldconfiguration is maintained to be the same irrespective of a UEconfiguration. In contrast, the DCI size/field configuration variesdepending on a UE configuration in the non-fallback DCI formats.

A CCE-to-REG mapping type is set to one of an interleaved type and anon-interleaved type.

-   -   Non-interleaved CCE-to-REG mapping (or localized CCE-to-REG        mapping): 6 REGs for a given CCE are grouped into one REG        bundle, and all of the REGs for the given CCE are contiguous.        One REG bundle corresponds to one CCE.    -   Interleaved CCE-to-REG mapping (or distributed CCE-to-REG        mapping): 2, 3 or 6 REGs for a given CCE are grouped into one        REG bundle, and the REG bundle is interleaved within a CORESET.        In a CORESET including one or two OFDM symbols, an REG bundle        includes 2 or 6 REGs, and in a CORESET including three OFDM        symbols, an REG bundle includes 3 or 6 REGs. An REG bundle size        is configured on a CORESET basis.

PDSCH carries downlink data (e.g., DL-SCH transport block, DL-SCH TB).The modulation scheme such as Quadrature Phase Shift Keying (QPSK), 16Quadrature Amplitude Modulation (QAM), 64 QAM, or 256 QAM is applied tothe PDSCH. A codeword is generated by encoding the TB. The PDSCH cancarry up to two codewords. Scrambling and modulation mapping areperformed for each codeword, and modulation symbols generated from eachcodeword may be mapped to one or more layers. Each layer is mapped toresources along with a demodulation reference signal (DMRS), isgenerated as an OFDM symbol signal, and is transmitted through acorresponding antenna port.

PUCCH carries Uplink Control Information (UCI). UCI may include one ormore of following information:

-   -   SR (Scheduling Request): Information used to request a UL-SCH        resource.    -   HARQ (Hybrid Automatic Repeat reQuest)-ACK (Acknowledgment): It        is a response to a downlink data packet (e.g., codeword) on the        PDSCH, and indicates whether the downlink data packet has been        successfully received. 1 bit of HARQ-ACK may be transmitted in        response to a single codeword, and 2 bits of HARQ-ACK may be        transmitted in response to two codewords. The HARQ-ACK response        includes positive ACK (simply, ACK), negative ACK (NACK), DTX or        NACK/DTX. Here, HARQ-ACK may be called as HARQ ACK/NACK and        ACK/NACK.    -   CSI (Channel State Information): feedback information for a        downlink channel. Multiple Input Multiple Output (MIMO)-related        feedback information includes a Rank Indicator (RI) and a        Precoding Matrix Indicator (PMI).

Table 5 shows PUCCH formats. According to PUCCH length, PUCCH formatscan be classified as Short PUCCH (format 0, 2) and Long PUCCH (format 1,3, 4).

TABLE 5 Length in PUCCH OFDM symbols Number format N_(symb) ^(PUCCE) ofbits Usage Etc 0 1-2 ≤2 HARQ, SR Sequence selection 1 4-14 ≤2 HARQ, [SR]Sequence modulation 2 1-2 >2 HARQ, CSI, CP-OFDM [SR] 3 4-14 >2 HARQ,CSI, DFT-s-OFDM [SR] (no UE multiplexing) 4 4-14 >2 HARQ, CSI,DFT-s-OFDM [SR] (Pre DFT OCC)

PUCCH format 0 carries UCI having a maximum size of 2 bits, and ismapped and transmitted based on a sequence. Specifically, the UEtransmits a specific UCI to the base station by transmitting one of theplurality of sequences through the PUCCH having the PUCCH format 0. TheUE transmits a PUCCH format 0 within a PUCCH resource for configuring acorresponding SR only when transmitting a positive SR.

PUCCH format 1 carries UCI with a maximum size of 2 bits, and amodulation symbol is spread by an orthogonal cover code (OCC)(configured differently depending on whether frequency hopping isperformed) in the time domain. DMRS is transmitted in a symbol in whicha modulation symbol is not transmitted (i.e., time division multiplexing(TDM) is performed).

PUCCH format 2 carries UCI having a bit size greater than 2 bits, and amodulation symbol is transmitted with DMRS based on frequency divisionmultiplexing (FDM). DM-RS is located at symbol indexes #1, #4, #7, and#10 in a given resource block with a density of 1/3. A Pseudo Noise (PN)sequence is used for the DM_RS sequence. For 2-symbol PUCCH format 2,frequency hopping may be enabled.

For PUCCH format 3, UE multiplexing is not performed in the samephysical resource blocks, and the PUCCH format 3 carries UCI having abit size greater than 2 bits. PUCCH resource of PUCCH format 3 does notinclude an orthogonal cover code. The modulation symbol is transmittedwith the DMRS based on time division multiplexing (TDM).

For PUCCH format 4, UE multiplexing is supported for up to 4 UEs in thesame physical resource blocks, and the PUCCH format 4 carries UCI havinga bit size greater than 2 bits. PUCCH resource of PUCCH format 3includes an orthogonal cover code. The modulation symbol is transmittedwith DMRS based on time division multiplexing (TDM).

PUSCH carries uplink data (e.g., UL-SCH transport block, UL-SCH TB)and/or uplink control information (UCI). PUCCH is transmitted based on aCP-OFDM (Cyclic Prefix -Orthogonal Frequency Division Multiplexing)waveform or a Discrete Fourier Transform-spread-Orthogonal FrequencyDivision Multiplexing (DFT-s-OFDM) waveform. When the PUSCH istransmitted based on the DFT-s-OFDM waveform, the UE performs transformprecoding for the PUSCH. For example, if transform precoding is notperformed (e.g., transform precoding is disabled), the UE transmits aPUSCH based on the CP-OFDM waveform. If transform precoding is performed(e.g., transform precoding is enabled), the UE transmits the PUSCH basedon a CP-OFDM waveform or a DFT-s-OFDM waveform. PUSCH transmission isdynamically scheduled by a UL grant in DCI (e.g., Layer 1 (PDCCH)signaling), and/or semi-statically scheduled based on higher layer(e.g., RRC) signaling (configured grant). PUSCH transmission may beperformed on a codebook-based or non-codebook-based basis.

FIG. 6 illustrates an ACK/NACK transmission example. Referring to FIG.6, the UE may detect the PDCCH in slot #n. Here, the PDCCH includesdownlink scheduling information (e.g., DCI formats 1_0, 1_1), and thePDCCH indicates a DL assignment-to-PDSCH offset (K0) and aPDSCH-HARQ-ACK reporting offset (K1). For example, DCI formats 1_0 and1_1 may include the following information:

-   -   Frequency domain resource assignment (FDRA): FDRA indicates the        RB set allocated to the PDSCH.    -   Time domain resource assignment (TDRA): TDRA indicates K0 (e.g.,        slot offset), the starting position (e.g., OFDM symbol index) of        the PDSCH within slot #n+K0, and the length of the PDSCH (e.g.,        the number of OFDM symbols).    -   PDSCH-to-HARQ_feedback timing indicator, which indicates K1        (e.g., slot offset)    -   HARQ process number (4 bits), which indicates the HARQ process        ID (Identity) for data (e.g., PDSCH, TB)    -   PUCCH resource indicator (PRI): PRI indicates a PUCCH resource        to be used for UCI transmission among a plurality of PUCCH        resources in the PUCCH resource set

UE start to receive the PDSCH in slot #(n+K0) based on the schedulinginformation received in slot #n. After completion of the PDSCH receptionin slot #n1 (where, n+K<n1), the UE may transmit UCI through PUCCH fromslot #(n1+K1). Here, the UCI may include a HARQ-ACK response for thePDSCH. In FIG. 6, for convenience, it is assumed that the SCS for thePDSCH and the SCS for the PUCCH are the same, and it is assumed thatslot # n1=slot # n+K0, but the present invention is not limited thereto.If the SCSs are different, K1 may be indicated/interpreted based on theSCS of the PUCCH.

If the PDSCH is configured to carry a maximum of 1 TB, the HARQ-ACKresponse may have 1-bit. When the PDSCH is configured to carry a maximumof 2 TBs, the HARQ-ACK response may be configured with 2-bits whenspatial bundling is not configured, and may be configured with 1-bitswhen spatial bundling is configured. When the HARQ-ACK transmission timefor the plurality of PDSCHs is configured as slot #(n+K1), the UCItransmitted in the slot #(n+K1) includes HARQ-ACK responses for theplurality of PDSCHs.

Whether the UE should perform spatial bundling for the HARQ-ACK responsemay be configured for each cell group (e.g., RRC/higher layersignaling). As an example, spatial bundling may be individuallyconfigured in each of the HARQ-ACK response transmitted through thePUCCH and/or the HARQ-ACK response transmitted through the PUSCH.

Spatial bundling may be supported when the maximum number of TBs (orcodewords) that can be received at one time in the corresponding servingcell (or schedulable through 1 DCI) is two (or two or more) (e.g.,higher layer parameter maxNrofCodeWordsScheduledByDCI is equal to 2-TB).Meanwhile, a number of layers greater than four may be used for 2-TBtransmission, and a maximum of four layers may be used for 1-TBtransmission. As a result, when spatial bundling is configured in acorresponding cell group, spatial bundling may be performed on a servingcell that can schedule more than four layers among serving cells in thecorresponding cell group. On a corresponding serving cell, a UE desiringto transmit a HARQ-ACK response through spatial bundling may generate aHARQ-ACK response by performing (bit-wise) logical AND operation on A/Nbits for a plurality of TBs.

For example, assuming that the UE receives DCI for scheduling 2-TB andreceives 2-TB through the PDSCH based on the DCI. If spatial bundling isperformed, a single A/N bit may be generated by performing a logical ANDoperation on the first A/N bit for the first TB and the second A/N bitfor the second TB. As a result, if both the first TB and the second TBare ACKs, the UE reports the ACK bit value to the base station, and wheneither TB is NACK, the UE reports the NACK bit value to the basestation.

A plurality of parallel DL HARQ processes can be configured for DLtransmission in the base station/terminal. A plurality of parallel HARQprocesses allow DL transmissions to be performed continuously whilewaiting for HARQ feedback on successful or unsuccessful reception of theprevious DL transmission. Each HARQ process is associated with a HARQbuffer of a MAC (Medium Access Control) layer. Each DL HARQ processmanages information related to the number of MAC PDU (Physical DataBlock) transmissions in the buffer, HARQ feedback for the MAC PDU in thebuffer, and a current redundancy version. Each HARQ process isidentified by a HARQ process ID.

FIG. 7 illustrates a PUSCH transmission example. Referring to FIG. 7,the UE may detect the PDCCH in slot #n. Here, the PDCCH includes uplinkscheduling information (e.g., DCI formats 0_0, 0_1). DCI formats 0_0 and0_1 may include the following information:

-   -   Frequency domain resource assignment (FDRA), which indicates the        RB set allocated to the PUSCH    -   Time domain resource assignment (TDRA), which indicates the slot        offset K2, the start position (e.g., symbol index) and length        (e.g., number of OFDM symbols) of the PUSCH in the slot. The        start symbol and length may be indicated through a Start and        Length Indicator Value (SLIV), or may be indicated respectively.

UE may transmit the PUSCH in slot #(n+K2) according to the schedulinginformation received in slot #n. The PUSCH may include a UL-SCH TB.

Beam Management (BM) Procedure

A DL BM procedure is described. DL BM procedure may include (1)transmission of beamformed DL RSs (e.g., CSI-RS or SS Block (SSB)) ofthe base station, and (2) beam reporting of the UE. Here, the beamreporting may include a preferred DL RS ID(s) and a correspondingreference signal received power (L1-RSRP). The DL RS ID may be an SSBResource Indicator (SSBRI) or a CSI-RS Resource Indicator (CRI).

The SSB beam and the CSI-RS beam may be used for beam measurement. Here,measurement metric may be L1-RSRP per resource/block. SSB may be usedfor coarse beam measurement, and CSI-RS may be used for fine beammeasurement. And, SSB can be used for both Tx beam sweeping and Rx beamsweeping. Rx beam sweeping using SSB may be performed at a UE bychanging the Rx beam for the same SSBRI across multiple SSB bursts.Here, one SS burst includes one or more SSBs, and one SS burst setincludes one or more SSB bursts.

The UE may receive RRC configuration regarding a list of maximum Mcandidate Transmission Configuration Indication (TCI) states for thepurpose of at least Quasi Co-location (QCL) indication. Here, M may be64. Each TCI state may be set to one RS set.

Each ID of DL RS for spatial QCL purpose (e.g., QCL Type D) in the RSset may be related to one of DL RS types such as SSB, P-CSI RS, SP-CSIRS, and A-CSI RS. At least, initialization/update of ID of DL RS(s) inRS set used for spatial QCL purpose can be performed through at leastexplicit signaling.

Table 6 shows an example of a TCI-State information element (IE). TheTCI-State IE associates one or two DL RSs to a corresponding QCL type.

TABLE 6 -- ASN1START -- TAG-TCI-STATE-START TCI-State ::= SEQUENCE { tci-StateId  TCI-StateId,  qcl-Type1  QCL-Info,  qcl-Type2  QCL-InfoOPTIONAL,  -- Need R  ... } QCL-Info ::= SEQUENCE {  cell  ServCellIndexOPTIONAL,  -- Need R  bwp-Id   BWP-Id  OPTIONAL, -- CondCSI-RS-Indicated  referenceSignal  CHOICE {   csi-rs  NZP-CSI-RS-ResourceId,   ssb    SSB-Index  },  qcl-Type  ENUMERATED{typeA, typeB, typeC, typeD},  ... } -- TAG-TCI-STATE-STOP -- ASN1STOP

In Table 6, the bwp-Id parameter indicates the DL BWP in which the RS islocated, the cell parameter indicates the carrier in which the RS islocated, and the referencesignal parameter indicates reference antennaport(s) which is a quasi co-location source for target antenna port (s)or a reference signal including the reference antenna port(s). Thetarget antenna port(s) may be an antenna port (s) of a CSI-RS, PDCCHDMRS, or PDSCH DMRS. For example, in order to indicate QCL reference RSinformation for NZP CSI-RS, a corresponding TCI state ID may beindicated through NZP CSI-RS resource configuration information. The TCIstate ID may be indicated through each CORESET configuration, therebyQCL reference information for the PDCCH DMRS antenna port(s) isindicated. The TCI state ID may be indicated through DCI, thereby QCLreference information for the PDSCH DMRS antenna port(s) is indicated.

Antenna port-QCL is defined so that a property of channel carrying asymbol on the antenna port is can be inferred/estimated from a propertyof a channel carrying another symbol on the same antenna port.

QCL related channel property includes one or more of Delay spread,Doppler spread, Frequency shift, Average received power, ReceivedTiming, and Spatial RX parameter. The Spatial Rx parameter means aspatial (reception) channel characteristic parameter such as angle ofarrival.

The UE may be configured with a list of maximum M TCI-States through thehigher layer parameter PDSCH-Config for PDSCH decoding according to adetected PDCCH having DCI intended for the UE and a given serving cell.The M depends on UE capability.

Each TCI-State includes parameters for configuring a quasi co-locationrelationship between one or two DL reference signals and a DM-RS port(s)of a PDSCH. The quasi co-location relationship is configured based on ahigher layer parameter ‘qcl-Type1’ for the first DL RS and a higherlayer parameter ‘qcl-Type2’ (if presented) for the second DL RS. In thecase of a corresponding configuration including QCL information for twoDL RSs, the QCL type is not the same regardless of whether the two DLRSs are QCLed with the same DL RS or different DL RSs. The quasico-location type corresponding to each DL RS is given by the higherlayer parameter ‘qcl-Type of QCL-Info’, and can be one of followingtypes:

-   -   ‘QCL-TypeA’: {Doppler shift, Doppler spread, average delay,        delay spread}    -   ‘QCL-TypeB’: {Doppler shift, Doppler spread}    -   ‘QCL-TypeC’: {Doppler shift, average delay}    -   ‘QCL-TypeD’: {Spatial Rx parameter}

For example, if a target antenna port(s) relates to a specific NZPCSI-RS, the corresponding NZP CSI-RS antenna ports areindicated/configured to be QCLed with a specific tracking referencesignal (TRS) from a QCL-Type A perspective, and with a specific SSB froma QCL-Type D perspective. The UE receiving the indication/configurationcan receive the corresponding NZP CSI-RS using the Doppler and delayvalues measured in QCL-TypeA TRS, and can apply a reception beam usedfor QCL-TypeD SSB reception to the corresponding NZP CSI-RS reception.The UE receives an activation command which is used for mapping amaximum 8 TCI states to values (field states) of ‘TransmissionConfiguration Indication field’ in DCI.

In the UL BM, beam reciprocity (or beam correspondence) between Tx beamsand Rx beams may or may not be established according to UEimplementation. If the reciprocity between the Tx beam and the Rx beamis established in both the base station and the UE, the UL beam pair maybe aligned through the DL beam pair. However, when the reciprocitybetween the Tx beam and the Rx beam is not established in either of thebase station and the UE, a UL beam pair determination process isrequired separately from the DL beam pair determination. Also, even whenboth the base station and the UE maintain beam correspondence, the basestation may use the UL BM procedure for determining the DL Tx beamwithout the UE requesting a report of the preferred beam. UL BM may beperformed through beamformed UL SRS transmission, and the ‘SRS-SetUse’parameter can be set to ‘BeamManagement’. Similarly, the UL BM proceduremay be divided into Tx beam sweeping of the UE and Rx beam sweeping ofthe base station. The UE may receive one or more Sounding ReferenceSymbol (SRS) resource sets configured by (higher layer parameter)SRS-ResourceSet (through higher layer signaling, RRC signaling, etc.).For each SRS resource set, the UE K SRS resources (higher laterparameter SRS-resource) may be configured. Here, K is a natural numberthat is equal to or greater than 1, and the maximum value of K isindicated by SRS_capability. Whether to apply the UL BM of the SRSresource set (higher layer parameter) is configured by SRS-SetUse. Whenthe SRS-SetUse is set to ‘BeamManagement (BM)’, only one SRS resourcecan be transmitted to each of a plurality of SRS resource sets at agiven time instant.

Cooperative transmission from multiple TRPs/panels/beams

A coordinated multi-point transmission (CoMP) was introduced in the LTEsystem and partly introduced in NR Rel-15. The CoMP can be related to(i) a method of transmitting the same signal or the same informationfrom multiple transmission and reception points (TRPs) (e.g., same layerjoint transmission), (ii) a method of transmitting by a specific TRP ata specific moment in consideration of radio channel quality or trafficload conditions while sharing information to be transmitted to UEbetween a plurality of TRPs (e.g., point selection), or (iii) a methodof transmitting different signals or information from a plurality ofTRPs to different spatial layers by spatial dimension multiplexing (SDM)(e.g., independent layer joint transmission), or other various ways. Asone example of the point selection methods, there is a dynamic pointselection (DPS) method in which an actual transmitting TRP can bechanged at each PDSCH transmission instance, and the QCL informationinforms the UE of which TRP is transmitting the PDSCH at present. Inthis regards, the QCL information can be used for indicating the UE canassume the same channel properties (e.g., Doppler shift, Doppler spread,average delay, delay spread, spatial RX parameter) between differentantenna ports. For example, when the PDSCH is to be transmitted inTRP#1, it is informed that the corresponding PDSCH DMRS antenna portsand a specific RS (e.g., CSI-RS resource#1) that has been used in TRP#1are QCLed. And when the PDSCH is to be transmitted in TRP#2, it isinformed that the corresponding PDSCH DMRS antenna ports and a specificRS (e.g., CSI-RS resource #2) that has been used in TRP#1 are QCLed. Forinstantaneous QCL information indication, a PDSCH quasi-colocationinformation (PQI) field was defined in DCI of LTE, and similarly atransmission configuration information (TCI) field is defined in NR. TheQCL indication/configuration method defined in the standard can be usednot only for cooperative transmission between a plurality of TRPs, butalso used for cooperative transmission between a plurality of panels(e.g., antenna groups) of the same TRP, or for cooperative transmissionbetween a plurality of beams of the same TRP, etc. This is because iftransmission panels or beams used in the same TRP are different, theDoppler, delay property, or reception beam (spatial Rx parameter) ofeach panel/beam may be different.

A method of Multiple TRPs/Panels/Beams are configured to transmitdifferent layer groups to the UE may be used and the method can becalled independent layer joint transmission (ILJT) or non-coherent jointtransmission (NCJT).

Multimedia Broadcast/Multicast Service (MBMS)

MBMS scheme deployed in 3GPP LTE is described. 3GPP MBMS can classifiedas (i) a single frequency network (SFN) scheme in which cells of aplurality of base stations are synchronized for transmitting the samedate through a PMCH channel, and (ii) a Single Cell Point To Multipoint(SC-PTM) scheme in which broadcasting is performed through PDCCH/PDSCHchannel in a corresponding cell coverage. Normally, the SFN scheme isused for providing the broadcast service over wide area (e.g. MBMS area)through pre-allocated semi-static resource(s), whereas the SC-PTM schemeis used for providing the broadcast service within a cell coveragethrough a dynamic resource(s).

Terms of 3GPP LTE MBMS are defined as follows:

-   -   MBSFN Synchronization Area: an area of the network where all        eNodeBs can be synchronized and perform MBSFN transmissions.        MBSFN Synchronization Areas are capable of supporting one or        more MBSFN Areas. On a given frequency layer, a eNodeB can only        belong to one MBSFN Synchronization Area. MBSFN Synchronization        Areas are independent from the definition of MBMS Service Areas    -   MBSFN Transmission or a transmission in MBSFN mode: a simulcast        transmission technique realised by transmission of identical        waveforms at the same time from multiple cells. An MBSFN        Transmission from multiple cells within the MBSFN Area is seen        as a single transmission by a UE.    -   MBSFN Area: an MBSFN Area consists of a group of cells within an        MBSFN Synchronization Area of a network, which are co-ordinated        to achieve an MBSFN Transmission. Except for the MBSFN Area        Reserved Cells, all cells within an MBSFN Area contribute to the        MBSFN Transmission and advertise its availability. The UE may        only need to consider a subset of the MBSFN areas that are        configured, i.e. when it knows which MBSFN area applies for the        service(s) it is interested to receive.

SC-PTM provides one logical channel named as SC-MCCH (Single CellMulticast Control Channel), and one or more logical channels named asSC-MTCH (Single Cell Multicast Traffic Channel). The logical channelsare mapped to a transport channel ‘DL-SCH’, and a physical channel‘PDSCH’. PDSCH carrying SC-MCCH or SC-MTCH data is scheduled by PDCCHscrambled with G-RNTI. Here, TMGI that corresponds to a service ID canbe mapped to a specific G-RNTI value (e.g., one-to-one mapping). Thus,if base station provides a plurality of services a plurality of G-RNTIvalues can be allocated for SC-PTM transmission. One or more UEs maymonitor PDCCH by using a specific G-RNTI for receiving a specificservice. For specific service/specific G-RNTI, an SC-PTM dedicated DRXon-duration can be configured. In this case, the UEs may wake-up for aspecific on-duration (s) and perform PDCCH monitoring based on G-RNTI.

HARQ-related operation for MBS

At least part of above paragraphs (e.g., 3GPP system, frame structure,NR system, etc.) can be referred to/coupled to/combined with one or moreembodiments of the invention will be explained below. In thespecification, ‘/’ may interpreted as ‘and’, ‘or’, or ‘and/or’ based onits context.

For supporting MBMS service in NR system, DL broadcast or DL multicasttransmission methods are discussed under Rel.-17 NR standard. Comparingwith DL unicast transmission to individual UE (i.e., point-to-point),the point-to-multipoint (PTM) transmission scheme such as MBMS isadvantageous for radio resource saving since multiple UEs can receiveone-time DL broadcast/multicast transmission of network.

In NR, a method in which the UE reports MBMS feedback (e.g., HARQfeedback for retransmission) to the base station for reliable DLbroadcast/multicast transmission is considered. The base station maytransmit different optimal beams to different UEs.

However, if PUCCH resources are commonly allocated to a plurality ofUEs, there is a problem that different UEs transmitting HARQ feedbackcannot transmit the PUCCH using individual UE optimal beams.

Therefore, according to an embodiment of the present invention,different PUCCH resources that are each mapped to a beam RS resource areallocated for a plurality of MBS PDSCHs transmitted through a pluralityof beam resources, and PDSCH and PUCCH resources are mapped to differentRS resources (e.g., via RRC or MAC CE or DCI), thereby reliable MBStransmission can be provided.

Meanwhile, regarding HARQ feedback transmission through PUCCH resources,a method for allocating a plurality of PUCCH resources for a pluralityof UEs is needed. Therefore, according to an embodiment of the presentinvention, for one or more PDSCH transmissions of the same MBS TB, amethod of configuring different PUCCH transmission resources for each UEis proposed.

Transmitter (e.g., Base Station)

For broadcasting the MBMS service in a cell, the base station maytransmit SIB1, MBMS SIB, one or more MCCHs, and one or more MTCHs. TheMCCH and the MTCH are logical channels and are transmitted through thephysical channel (s), PDSCH(s), and are scheduled through the PDCCH (s).The MCCH transmits MBMS control information, and one MTCH transmitsspecific MBMS service data.

The base station provides BWP for MBMS (i.e., MBMS BWP) to UEs. MBMS BWPcan be divided into MBMS SIB DL BWP and MBMS SIB UL BWP for MBMS SIBtransmission and reception, MCCH DL BWP and MCCH UL BWP for MCCHtransmission and reception, and MTCH DL BWP and MTCH UL BWP for MTCHtransmission and reception. One cell may provide zero, one or more MBMSDL BWPs and zero, one or more MBMS UL BWPs. Accordingly, the basestation supporting MBMS may provide all of the above MBMS BWP typesseparately from the existing Initial BWP or UE-dedicated BWP, or mayprovide only zero or some MBMS BWPs. Some or all MBMS BWPs may be thesame as or different from the conventional Initial BWP or Default BWP orfirst active BWP or active BWP.

UE may configure SC-RNTI and MCCH transmission according to MBMS SIB orMBMS control information provided by the base station. MBMS SIB or MBMScontrol information may include configuration information for DL BWPand/or UL BWP for MBMS.

The MBMS SIB or MBMS control information may include at least some ofthe following information.

-   -   PUCCH resource sets for MBMS feedback: Common PUCCH resource        mapped to specific service ID (e.g., TMGI) or specific G-RNTI or        specific MBMS DL BWP or specific MTCH(s) or specific MCCH(s).        Or, UE-dedicated PUCCH resources used by individual UEs        receiving a specific service or specific G-RNTI based        transmission.    -   RACH resource for MBMS feedback: RACH resource information        mapped to a specific service ID (e.g., TMGI) or specific G-RNTI        or specific MBMS DL BWP or specific MTCH(s) or specific MCCH(s).        For example, a specific RACH preamble, Preamble Occasion, or        RACH occasion may be mapped to a specific service ID (TMGI), a        specific G-RNTI, a specific MBMS DL BWP, or a specific MTCH(s)        or a specific MCCH(s).

The base station provides MBMS through UL BWP and/or DL BWP. Forexample, MCCH control information and MTCH are provided through DL BWP.Meanwhile, through the UL BWP, MBMS feedback for PDSCH for MCCH or MBMSfeedback for PDSCH for MTCH is provided. The UL BWP may be used forreporting HARQ ACK/NACK of MBMS feedback or MBMS -related SSB/CSI-RSmeasurement result.

The base station may configure UE common PUCCH resource sets for aspecific UL BWP of a specific cell for MBMS feedback. The UE commonPUCCH resource set is used by UEs performing HARQ feedback for aspecific MBS PDSCH, and the base station may configure the UE commonPUCCH resource set as shown in Table 7 below.

TABLE 7 PUCCH-ResourceSet ::= SEQUENCE {  pucch-ResourceSetIdPUCCH-ResourceSetId,  resourceList SEQUENCE (SIZE(1..maxNrofPUCCH-ResourcesPerSet)) OF PUCCH- ResourceId,  maxPayloadSizeINTEGER (4..256) OPTIONAL -- Need R } PUCCH-Resource ::= SEQUENCE { pucch-ResourceId PUCCH-ResourceId,  starting PRB PRB-Id, intraSlotFrequencyHopping ENUMERATED { enabled } OPTIONAL, -- Need R secondHopPRB PRB-Id OPTIONAL, -- Need R  format CHOICE {   format0PUCCH-format0,   format1 PUCCH-format1,   format2 PUCCH-format2,  format3 PUCCH-format3,   format4 PUCCH-format4} }

One or more M ICH data or one or more MUCH data may be included in oneMBS Transport Block (TB) for DL transmission. The base station transmitsone MBS TB through PDSCH for MBS. In FIG. 8, one MBS PDSCH transmissionis scheduled through DCI of the PDCCH. CRC of DCI may be scrambled withG-RNTI. A plurality of UEs may receive the DCI, decode the PDSCHindicated by the DCI, and receive one MBS TB.

If a plurality of UEs need to receive through different beams, the basestation may transmit different MBS PDSCHs on different beam RSs of onecell. In this case, different MBS PDSCHs may be used to repeatedlytransmit the same MBS TB. For example, in FIG. 8, all MBS PDSCHsrepeatedly transmit the same MBS TB, and different MBS PDSCHtransmissions may be associated with different RSs. For example, one ormore SSB indexes of the cell are mapped to one MBS PDSCH transmission.For example, SSB index 1 may be mapped to MBS PDCCH/PDSCH1, SSB index 2may be mapped to MBS PDCCH/PDSCH2, SSB index 3 may be mapped to MBSPDCCH/PDSCH3, and the like. Alternatively, one or more CSI-RS resourcesof the cell may be mapped to one MBS PDSCH transmission.

FIG. 8 illustrates PDSCH retransmission according to an embodiment ofthe present invention. The PDSCH retransmission may be MBS PDSCHretransmissions performed based on UE common PUCCH.

The base station provides one or more CORESET and Search Space Set (SSS)through one or more DL BWPs for MBS PDCCH monitoring. One or more TCIstates, one or more SSB indexes, one or more CSI-RS resources may bemapped to one or more CORESETs and/or SSSs.

Receiver (e.g., UE):

RRC connected UE may select a CORESET and a search space set accordingto its current TCI state, and may receive the DCI by monitoring thePDCCH through the selected SSS. Idle or inactive UE periodicallymeasures the SSB index or CSI-RS resource, selects the CORESET andSearch Space Set mapped to the SSB index or CSI-RS resource exceeding athreshold, and monitors the PDCCH through the selected SSS to receiveDCI.

The UE monitors the MBS PDCCH through the DL BWP for the MBS. If thereare CORESET and SSS mapped to a current TCI state or SSB index/CSI-RSresource exceeding the threshold in a plurality of DL BWPs, theidle/inactive UE selects an initial BWP or a DL BWP that overlaps withthe initial BWP, and the connected UE selects a currently active BWP orconfigured BWP or a DLBWP that overlaps with the currently active BWP orconfigured BWP.

The UE monitors the MBS PDCCH through the selected DL BWP. If there area plurality of CORESETs and SSSs mapped to the current TCI state or theSSB index/CSI-RS resource exceeding the threshold, UE may select aCORESET and SSS not overlapped with other transmission/receptionoperations of the UE, or select the closest CORESET and SSS.

The UE monitors the PDCCH through the selected CORESET and SSS, andreceives DCI through the PDCCH. The DCI in which the CRC is scrambled isdecoded with the G-RNTI of the MBS service that the UE wants to receive.

The DCI scrambled by the G-RNTI may include at least some of thefollowing information:

-   -   Identifier for DCI formats    -   Frequency domain resource assignment    -   SS/PBCH index or CSI-RS resource indicator or TCI state Id    -   Time domain resource assignment    -   VRB-to-PRB mapping    -   Modulation and coding scheme    -   New data indicator    -   Redundancy version    -   HARQ process number

The UE receives the PDSCH indicated by the DCI. Here, ‘SS/PBCH index orCSI-RS resource indicator or TCI state Id’ indicates an SS/PBCH index orCSI-RS resource indicator or TCI state Id associated with the indicatedPDSCH. The UE receives the PDSCH according to the indicated SS/PBCHindex or CSI-RS resource indicator or TCI state Id.

DCI may include at least the following information to allocate PUCCHresources for HARQ feedback.

-   -   HARQ feedback enabling indicator—1 bit        -   TPC command for scheduled PUCCH—2 bits        -   PUCCH resource indicator—3 bits        -   PDSCH-to-HARQ_feedback timing indicator—3 bits        -   A/N or NACK only

If the HARQ feedback enabling indicator=0 in the n-th transmitted DCI,the UE assumes that the DCI does not include the TPC command forscheduled PUCCH, PUCCH resource indicator, and PDSCH-to-HARQ_feedbacktiming indicator, and does not transmit HARQ feedback for the n-th PDSCHindicated by the DCI.

If HARQ feedback enabling indicator=1, the UE assumes that the TPCcommand for scheduled PUCCH, PUCCH resource indicator, PDSCH-to-HARQfeedback timing indicator is included in the corresponding DCI, andtransmits HARQ feedback for the n-th PDSCH transmission through thePUCCH resource indicated by DCI. In this case, the UE performs PUCCHtransmission through the PUCCH resource based on the SS/PBCH index orCSI-RS resource indicator or TCI state Id indicated in the correspondingDCI. UCI included in PUCCH includes HARQ feedback information. HARQfeedback information is determined as ACK or NACK according to thedecoding result of the n-th PDSCH transmission indicated by thecorresponding DCI. If the UE knows that the nth PDSCH transmission isthe last transmission for the corresponding MBS TB (e.g., when the lastretransmission is indicated by the corresponding DCI), the UE may skipthe PUCCH transmission. Alternatively, when the n-th PDSCH transmissionis the last transmission for the corresponding MBS TB, the base stationindicates that the n-th DCI is the last transmission of thecorresponding MBS TB, and configures HARQ feedback enabling indicator=0.

The base station transmits beams related to different SS/PBCH indexes,CSI-RS resource indicators, and/or TCI states for different PDSCHtransmissions for transmitting the same MBS TB. That is, in FIG. 8,different PDSCH transmissions such as PDSCH1, PDSCH2, and PDSCH3 arerelated to different SS/PBCH or CSI-RS resources or TCI states.

The UE receives one or more of a plurality of PDSCH that carry the sameMBS TB. For example, when SSB indices 1 and 2 are above the threshold,the UE may receive both PDSCH1 and PDSCH2. Or UE may receive eitherPDSCH1 or PDSCH2. When the PDCCH for PDSCH1 or the PDCCH for PDSCH2indicates HARQ feedback enabling indicator=1, the UE selects one PDSCHresource among the received PDSCHs, and transmits HARQ feedback usingthe PUCCH resource mapped to the selected PDSCH. For example, the UEtransmits the PUCCH by using the SSB index for the selected PDSCH,CSI-RS resource, or TCI state. For example, the UE selects one of PDSCH1or PDSCH2. If PDSCH2 is selected, PUCCH transmission is performedaccording to the PUCCH resource mapped to PDSCH2 and SSB index 2associated with PDSCH2. PUCCH transmits HARQ feedback according to theMBS TB decoding result of PDSCH1 or PDSCH2. If one of the decodingresults is ACK, ACK is transmitted, and otherwise, NACK is transmitted.

If a corresponding SSB index, CSI-RS resource, and/or TCI state is notindicated by DCI, the base station may configure, through an RRCmessage, an SSB index, a CSI-RS resource and/or TCI state mapped to eachPUCCH resource. For example, one or more SSB indexes, or one or moreCSI-RS resources, or one or more TCI states may be configured for onePUCCH resource through an RRC message. If the UE transmits a PUCCH forthe PUCCH resource indicated by the DCI, the PUCCH transmission for theHARQ A/N is performed according to the SSB index, or the CSI-RS resourceor the TCI state mapped to the resource.

Meanwhile, the base station may transmit a MAC CE to activate one ormore SSB indexes, or one or more CSI-RS resources, one or more TCIstates. For example, through a specific MAC-CE command (e.g., PUCCHspatial relation Activation/Deactivation), an SSB index/CSI-RSresource/TCI state from among SSB indexes/CSI-RS resources/TCI statesassociated with a specific PUCCH resource configured through an RRCmessage, is activated.

FIG. 9 illustrates allocation and transmission of UE common PUCCHresource mapped to MBS PDSCH retransmission and SSB index according toan embodiment of the present invention.

Referring to FIG. 9, the base station may indicate the same PUCCHresource for different PDSCH transmissions related to different SSBindexes. For example, when the PDSCH2 related to SSB#2 and the PDSCH3related to SSB#3 transmit the same MBS TB, the PDCCH for PDSCH2 and thePDCCH for PDSCH3 can indicate the same PUCCH resource. A UE receivingPDSCH2 and a UE receiving PDSCH3 may use the same PUCCH resource, buttransmit HARQ A/N based on SSB#2 and SSB#3, respectively.

If the base station cannot allocate the PUCCH resource for a specificSSB index, the base station can disable HARQ A/N transmission by settingthe HARQ feedback enabling indicator=0 in the DCI that schedules thePDSCH for the corresponding SSB index.

Alternatively, when the UE cannot transmit PUCCH based on thecorresponding SSB index, CSI-RS resource and/or TCI state, HARQ A/Ntransmission may be deactivated. Or, when the UE cannot transmit PUCCHbased on the corresponding SSB index, CSI-RS resource and/or TCI state,HARQ A/N transmission is performed through a PUCCH resourcecorresponding to another SSB index/CSI-RS resource and/or TCI statehigher than the threshold. Alternatively, the HARQ A/N may betransmitted through UCI of PUSCH. Alternatively, when the PUCCHtransmission cannot be performed due to a collision with anothertransmission/reception operation of the UE, the HARQ A/N is deactivatedor the HARQ A/N is transmitted through the PUSCH or UCI of the UEdedicated PUCCH. In this case, the UCI include informationindicating/identifying the received PDSCH.

The base station may perform PDSCH retransmission according to HARQ A/Nreceived from one or more UEs. The PDSCH (re)transmission can bedetermined based on HARQ A/N of PUCCH transmission for each SSBindex/CSI-RS resource/TCI state. For example, as shown in FIG. 8, whenACK is received for SSB#1 or when NACK is not received, the base stationdoes not retransmit PDSCH2 for SSB#1. If ACK is not received for SSB#2,or if NACK is received, the base station performs PDSCH2 retransmissionrelated to SSB#2.

In an embodiment of the present invention, different PUCCH resourceseach mapped to each beam resource can be allocated for a plurality ofMBS PDSCHs on a plurality of beam resources, so that reliable MBStransmission can be supported.

PDSCH-to-HARQ Feedback Timing for DCI-Based Individual PUCCH Resources

A UE may determine a UE common PUCCH resource based on K1 timingindicated by each DCI for each PDSCH and perform PUCCH transmission. Forexample, FIG. 8 illustrates an example of DCI-basedPDSCH-to-HARQ_feedback timing determination for individual PUCCHresources. Here, K1=3 is indicated for PDSCH1, and K1=2 is indicated forPDSCH3. Therefore, for HARQ A/N information for PDSCH1, a correspondingPUCCH resource (e.g., a PUCCH resource indicated by the PUCCH resourceindicator in DCI) is configured in a time resource where an offsetbetween the PDSCH and the PUCCH being 3 slots. For HARQ A/N informationfor PDSCH3, a corresponding PUCCH resource is configured in a timeresource where an offset between the PDSCH and PUCCH being 2 slots. Inthe case of TDD, PDSCH and PUCCH resources can be located in the sameBWP or overlapping BWP(s). In the case of FDD, the UL BWP for the PUCCHresource of PDSCH1 or PDSCH3 is determined according to DCI or PUCCHresource indicator or RRC configuration.

The first PUCCH Resource-Based PDSCH-to-HARQ Timing Indication throughDCI

FIG. 10 illustrates an example of the first PUCCH resource-basedPDSCH-to-HARQ timing (K1) indication through DCI.

As shown in FIG. 10, DCIs for scheduling a plurality of PDSCHstransmitting the same TB may indicate each K1 value based on a relativeposition from each PDSCH scheduled by corresponding DCI to the firstPUCCH resource from among a corresponding set of a plurality of PUCCHresources. Here, the first PUCCH resource may be a PUCCH resource forthe first PDSCH from among the plurality of PDSCHs carrying the same TB.For example, all the PDSCHs transmitting the same MBS TB may beconfigured with its K1 timing based on the same first PUCCH resource(e.g., the PUCCH resource for PDSCH1). For example, K1=3 is indicatedfor PDSCH1, and K1=2 is indicated for PDSCH3. Accordingly, the slotoffset between the first PUCCH and PDSCH1 is 3 slots, and the slotoffset between the first PUCCH and PDSCH3 is 2 slots. For example, HARQA/N for PDSCH1 can be transmitted on the first PUCCH resource, whereasHARQ A/N for PDSCH3 can be transmitted on the 3rd PUCCH resource ratherthan the first PUCCH resource. The offset/distance(s) between the firstPUCCH and subsequent PUCCH resource(s) may be configured by the basestation, for example, configured through the PUCCH resource sets of theRRC message, through DCI, or through MAC CE.

Meanwhile, each PUCCH resource may be a UE dedicated resource. Forexample, the base station may configure a plurality of PUCCH resourcesfor one PDSCH transmission scheduled by G-RNTI DCI. In this case,different PUCCH resources may be allocated to different UEs receivingthe corresponding PDSCH transmission, respectively. In the case of PDSCHtransmission for multicast, the base station may assign an index to eachUE belonging to the multicast group. Each UE receiving the PDSCHtransmission selects a PUCCH resource mapped to its own index from amonga plurality of PUCCH resources indicated by the DCI. For example, if acorresponding index=3, the 3rd PUCCH resource in ascending/descendingorder in time or frequency domain can be selected. RRC or MAC CE or DCImay indicate whether a corresponding resource is a UE dedicatedresource.

After receiving the PDSCH selected according to SSB index, CSI-RSresource and/or TCI state, the UE may determine HARQ A/N based on thePDSCH decoding result, and selects the first PUCCH resource locationdescribed above, identify the first PUCCH resource and transmit HARQ A/Non a UE dedicated PUCCH resource determined based on an index and theidentified the first PUCCH resource.

Identical PDSCH-to-HARQ Feedback Timing

FIG. 11 illustrates an example of fixed PDSCH-to-HARQ_feedback timingdetermination.

As shown in FIG. 11, for a plurality of PDSCHs transmitting the same TB,each of PUCCH resources associated with each PDSCH can be configuredbased on an identical K1 value (e.g., the same slot offset). Here, theidentical K1 value may be a constant/fixed/predetermined timing/offset.For example, in FIG. 11, all PDSCHs of the lower BWP can be configuredwith K1=3, and all of the PDSCHs of the upper BWP can be configured withK1=2. For HARQ A/N information for PDSCH1, a PUCCH resource (indicatedby PUCCH resource indicator of DCI) can be configured in a time resourcewhere an offset between the PDSCH and the PUCCH being 3 slots. For HARQA/N information for PDSCH3, a PUCCH resource can be configured on a timeresource where an offset between the PDSCH and PUCCH being 2 slots. Inthe case of TDD, PDSCH and PUCCH resources may be located in the sameBWP or overlapping BWP(s). In the case of FDD, an identical (fixed) K1value can be configured/determined based on a UL BWP in which the PUCCHresource is configured a DL BWP in which the PDSCH resource isconfigured (e.g., through DCI or PUCCH resource indicator or RRCconfiguration).

Periodicity-Based PDSCH-to-HARQ Feedback Timing Determination

FIG. 12 illustrates an example of Periodicity-basedPDSCH-to-HARQ_feedback timing determination.

As shown in FIG. 12, for a plurality of PDSCHs transmitting the same TB,a time period (e.g., on duration for MBS) in which the n-th PDSCHtransmissions are performed and a time period (e.g., on duration forMBS) in which the n+1-th PDSCH transmissions are performed can beconfigured based on a periodic retransmission cycle. For example, then-th PDSCH transmissions may occur in an on duration for MBS period of acertain retransmission cycle, and an HARQ feedback period including aplurality of PUCCH resources for the n-th PDSCH transmissions can beconfigured after the on duration for MBS period. The time offset fromthe first PUCCH to the first PDCCH or the first PDSCH or the last PDCCHor the last PDSCH of the n-th PDSCH transmissions may beconfigured/signaled by the base station (e.g., DCI or MAC CE or RRCmessage). Alternatively, the base station may configure the offsetbetween a start time of the HARQ feedback period or a last time of theon duration for MBS and the first PUCCH resource (e.g., DCI or MAC CE orRRC message). The base station also may configure the on duration forMBS and/or the retransmission cycle length (e.g., DCI or MAC CE or RRCmessage). Each PUCCH resource may be a UE common PUCCH resource or a UEdedicated PUCCH resource.

The interval/offset(s) of the first PUCCH and subsequent PUCCHresource(s) may be configured by the base station (e.g., DCI or MAC CEor RRC message PUCCH resource set)

Each PUCCH resource may be a UE dedicated resource. For example, thebase station may configure a plurality of PUCCH resources for one PDSCHtransmission scheduled by G-RNTI DCI. Different PUCCH resources may beallocated to different UEs receiving the corresponding PDSCHtransmission, respectively. In the case of PDSCH transmission formulticast, the base station may assign an index to each UE belonging tothe multicast group. Each UE receiving the PDSCH transmission selects aPUCCH resource mapped to its own index from among a plurality of PUCCHresources indicated by the DCI. For example, for an index=3, the 3rdPUCCH resource in ascending/descending order in time or frequency domaincan be selected. RRC or MAC CE or DCI may indicate whether acorresponding resource is a UE dedicated resource.

After receiving the PDSCH selected according to SSB index, CSI-RSresource and/or TCI state, the UE may determine HARQ A/N based on thePDSCH decoding result, and selects the first PUCCH resource locationdescribed above, identify the first PUCCH resource and transmit HARQ A/Non a UE dedicated PUCCH resource determined based on an index and theidentified the first PUCCH resource.

In different PDSCH-to-HARQ_feedback timing determination examplesdescribed above, different PUCCH resources may be mapped to differentSSB indexes or CSI-RS resources or TCI states, may be mapped todifferent UEs, may be mapped to different UE groups, and may be mappedto different services or G-RNTIs.

Meanwhile, in the above examples, the base station may provide the MBSTB to a specific UE as a UE dedicated PDSCH. UE dedicated PUCCH resourcemay be separately allocated through DCI for the UE dedicated PDSCH. Sucha UE dedicated PUCCH resource may be temporarily allocated through atime/frequency resource separate from the above examples.

As described above, according to an embodiment of the present invention,HARQ feedback is provided for reliable MBS transmission, and a method ofdetermining PUCCH resources is proposed such that multiple UEs cantransmit HARQ feedback for the same MBS TB transmission.

FIG. 13 illustrates a method of receiving a signal by a user equipmentin an embodiment of the present invention.

Referring to FIG. 13, a UE may receive one or more physical downlinkcontrol channels (PDCCHs) each carrying downlink control information(DCI) including a field indicating a transmitting configuration index(TCI) state (D05). The UE may determine, for each TCI state, whether ahybrid automatic repeat request (HARQ) operation is enabled or disabled.

The UE may receiving, based the one or more PDCCHs, one or more of aplurality of physical downlink shared channels (PDSCHs) (D10). Theplurality of PDSCHs can be configured to carry a same transport block(TB) in a plurality of TCI states, respectively.

The UE may transmit HARQ-acknowledgement (ACK) information for the sameTB through a physical uplink control channel (PUCCH) associated with anHARQ operation-enabled TCI state (D15).

The plurality of PDSCHs may be related to different TCI states,respectively.

Each DCI of each PDCCH may include information indicating whether theHARQ operation is enabled or disabled for a corresponding TCI state.

A PUCCH transmit power control (TPC) command may be omitted incorresponding DCI which disables the HARQ operation for a correspondingTCI state.

The UE may obtain the PUCCH TPC command only from HARQ operationenabling-DCI.

The DCI in each PDCCH may schedule each PDSCH.

A resource of the PUCCH can be indicated by corresponding DCI associatedwith the HARQ operation-enabled TCI state.

The one or more PDSCHs received by the UE can be selected from among theplurality of the PDSCHs, based on each reference signal measurementperformed for each TCI state.

The UE may perform one or more PUCCH transmissions related to the sameTB reception, based on each reference signal measurement performed foreach TCI state.

The same TB carried by the plurality of the PDSCHs may be related to amulticast broadcast service (MBS). The DCI may be common for a group ofUEs receiving the MBS.

FIG. 14 illustrates a communication system 1 applied to the presentdisclosure.

Referring to FIG. 14, a communication system 1 applied to the presentdisclosure includes wireless devices, Base Stations (BSs), and anetwork. Herein, the wireless devices represent devices performingcommunication using Radio Access Technology (RAT) (e.g., 5G New RAT(NR)) or Long-Term Evolution (LTE)) and may be referred to ascommunication/radio/5G devices. The wireless devices may include,without being limited to, a robot 100 a, vehicles 100 b-1 and 100 b-2,an eXtended Reality (XR) device 100 c, a hand-held device 100 d, a homeappliance 100 e, an Internet of Things (IoT) device 100 f, and anArtificial Intelligence (AI) device/server 400. For example, thevehicles may include a vehicle having a wireless communication function,an autonomous driving vehicle, and a vehicle capable of performingcommunication between vehicles. Herein, the vehicles may include anUnmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may includean Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) deviceand may be implemented in the form of a Head-Mounted Device (HMD), aHead-Up Display (HUD) mounted in a vehicle, a television, a smartphone,a computer, a wearable device, a home appliance device, a digitalsignage, a vehicle, a robot, etc. The hand-held device may include asmartphone, a smartpad, a wearable device (e.g., a smartwatch or asmartglasses), and a computer (e.g., a notebook). The home appliance mayinclude a TV, a refrigerator, and a washing machine. The IoT device mayinclude a sensor and a smartmeter. For example, the BSs and the networkmay be implemented as wireless devices and a specific wireless device200 a may operate as a BS/network node with respect to other wirelessdevices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. Vehicle-to-Vehicle(V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as uplink/downlinkcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, Integrated AccessBackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the present disclosure.

FIG. 15 illustrates wireless devices applicable to the presentdisclosure.

Referring to FIG. 15, a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through a variety of RATs (e.g.,LTE and NR). Herein, {the first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. 14.

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store a variety of informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the present disclosure, the wireless devicemay represent a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process informationwithin the memory(s) 204 to generate third information/signals and thentransmit radio signals including the third information/signals throughthe transceiver(s) 206. The processor(s) 202 may receive radio signalsincluding fourth information/signals through the transceiver(s) 106 andthen store information obtained by processing the fourthinformation/signals in the memory(s) 204. The memory(s) 204 may beconnected to the processor(s) 202 and may store a variety of informationrelated to operations of the processor(s) 202. For example, thememory(s) 204 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 202 and the memory(s) 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 206 may be connected to the processor(s) 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the present disclosure, the wireless device may represent acommunication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more Protocol Data Units (PDUs) and/or one or more Service Data Unit(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands Theone or more memories 104 and 204 may be configured by Read-Only Memories(ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable Read-Only Memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother devices. For example, the one or more transceivers 106 and 206 maybe connected to the one or more processors 102 and 202 and transmit andreceive radio signals. For example, the one or more processors 102 and202 may perform control so that the one or more transceivers 106 and 206may transmit user data, control information, or radio signals to one ormore other devices. The one or more processors 102 and 202 may performcontrol so that the one or more transceivers 106 and 206 may receiveuser data, control information, or radio signals from one or more otherdevices. The one or more transceivers 106 and 206 may be connected tothe one or more antennas 108 and 208 and the one or more transceivers106 and 206 may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, through the one ormore antennas 108 and 208. In this document, the one or more antennasmay be a plurality of physical antennas or a plurality of logicalantennas (e.g., antenna ports). The one or more transceivers 106 and 206may convert received radio signals/channels etc. from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc. using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels, etc.processed using the one or more processors 102 and 202 from the baseband signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters.

FIG. 16 illustrates another example of a wireless device applied to thepresent disclosure. The wireless device may be implemented in variousforms according to a use-case/service (refer to FIG. 16).

Referring to FIG. 16, wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 15 and may be configured by variouselements, components, units/portions, and/or modules. For example, eachof the wireless devices 100 and 200 may include a communication unit110, a control unit 120, a memory unit 130, and additional components140. The communication unit may include a communication circuit 112 andtransceiver(s) 114. For example, the communication circuit 112 mayinclude the one or more processors 102 and 202 and/or the one or morememories 104 and 204 of FIG. 15. For example, the transceiver(s) 114 mayinclude the one or more transceivers 106 and 206 and/or the one or moreantennas 108 and 208 of FIG. 15. The control unit 120 is electricallyconnected to the communication unit 110, the memory 130, and theadditional components 140 and controls overall operation of the wirelessdevices. For example, the control unit 120 may control anelectric/mechanical operation of the wireless device based onprograms/code/commands/information stored in the memory unit 130. Thecontrol unit 120 may transmit the information stored in the memory unit130 to the exterior (e.g., other communication devices) via thecommunication unit 110 through a wireless/wired interface or store, inthe memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be variously configured according totypes of wireless devices. For example, the additional components 140may include at least one of a power unit/battery, input/output (I/O)unit, a driving unit, and a computing unit. The wireless device may beimplemented in the form of, without being limited to, the robot (100 aof FIG. 14), the vehicles (100 b-1 and 100 b-2 of FIG. 14), the XRdevice (100 c of FIG. 14), the hand-held device (100 d of FIG. 14), thehome appliance (100 e of FIG. 14), the IoT device (100 f of FIG. 14), adigital broadcast terminal, a hologram device, a public safety device,an MTC device, a medicine device, a fintech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 14), the BSs (200 of FIG. 14), a networknode, etc. The wireless device may be used in a mobile or fixed placeaccording to a use-example/service.

In FIG. 16, the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor, an Electronic Control Unit (ECU), agraphical processing unit, and a memory control processor. As anotherexample, the memory 130 may be configured by a Random Access Memory(RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory,a volatile memory, a non-volatile memory, and/or a combination thereof.

FIG. 17 illustrates a vehicle or an autonomous driving vehicle appliedto the present disclosure. The vehicle or autonomous driving vehicle maybe implemented by a mobile robot, a car, a train, a manned/unmannedAerial Vehicle (AV), a ship, etc.

Referring to FIG. 17, a vehicle or autonomous driving vehicle 100 mayinclude an antenna unit 108, a communication unit 110, a control unit120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140c, and an autonomous driving unit 140 d. The antenna unit 108 may beconfigured as a part of the communication unit 110. The blocks110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. 16,respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous driving vehicle 100. The control unit 120 mayinclude an Electronic Control Unit (ECU). The driving unit 140 a maycause the vehicle or the autonomous driving vehicle 100 to drive on aroad. The driving unit 140 a may include an engine, a motor, apowertrain, a wheel, a brake, a steering device, etc. The power supplyunit 140 b may supply power to the vehicle or the autonomous drivingvehicle 100 and include a wired/wireless charging circuit, a battery,etc. The sensor unit 140 c may acquire a vehicle state, ambientenvironment information, user information, etc. The sensor unit 140 cmay include an Inertial Measurement Unit (IMU) sensor, a collisionsensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor,a heading sensor, a position module, a vehicle forward/backward sensor,a battery sensor, a fuel sensor, a tire sensor, a steering sensor, atemperature sensor, a humidity sensor, an ultrasonic sensor, anillumination sensor, a pedal position sensor, etc. The autonomousdriving unit 140 d may implement technology for maintaining a lane onwhich a vehicle is driving, technology for automatically adjustingspeed, such as adaptive cruise control, technology for autonomouslydriving along a determined path, technology for driving by automaticallysetting a path if a destination is set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, etc. from an external server. The autonomous drivingunit 140 d may generate an autonomous driving path and a driving planfrom the obtained data. The control unit 120 may control the drivingunit 140 a such that the vehicle or the autonomous driving vehicle 100may move along the autonomous driving path according to the driving plan(e.g., speed/direction control). In the middle of autonomous driving,the communication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. In themiddle of autonomous driving, the sensor unit 140 c may obtain a vehiclestate and/or surrounding environment information. The autonomous drivingunit 140 d may update the autonomous driving path and the driving planbased on the newly obtained data/information. The communication unit 110may transfer information about a vehicle position, the autonomousdriving path, and/or the driving plan to the external server. Theexternal server may predict traffic information data using AItechnology, etc., based on the information collected from vehicles orautonomous driving vehicles and provide the predicted trafficinformation data to the vehicles or the autonomous driving vehicles.

FIG. 18 is a diagram illustrating a DRX operation of a UE according toan embodiment of the present disclosure.

The UE may perform a DRX operation in the afore-described/proposedprocedures and/or methods. A UE configured with DRX may reduce powerconsumption by receiving a DL signal discontinuously. DRX may beperformed in an RRC_IDLE state, an RRC_INACTIVE state, and anRRC_CONNECTED state. The UE performs DRX to receive a paging signaldiscontinuously in the RRC_IDLE state and the RRC_INACTIVE state. DRX inthe RRC_CONNECTED state (RRC_CONNECTED DRX) will be described below.

Referring to FIG. 18, a DRX cycle includes an On Duration and anOpportunity for DRX. The DRX cycle defines a time interval betweenperiodic repetitions of the On Duration. The On Duration is a timeperiod during which the UE monitors a PDCCH. When the UE is configuredwith DRX, the UE performs PDCCH monitoring during the On Duration. Whenthe UE successfully detects a PDCCH during the PDCCH monitoring, the UEstarts an inactivity timer and is kept awake. On the contrary, when theUE fails in detecting any PDCCH during the PDCCH monitoring, the UEtransitions to a sleep state after the On Duration. Accordingly, whenDRX is configured, PDCCH monitoring/reception may be performeddiscontinuously in the time domain in the afore-described/proposedprocedures and/or methods. For example, when DRX is configured, PDCCHreception occasions (e.g., slots with PDCCH SSs) may be configureddiscontinuously according to a DRX configuration in the presentdisclosure. On the contrary, when DRX is not configured, PDCCHmonitoring/reception may be performed continuously in the time domain.For example, when DRX is not configured, PDCCH reception occasions(e.g., slots with PDCCH SSs) may be configured continuously in thepresent disclosure. Irrespective of whether DRX is configured, PDCCHmonitoring may be restricted during a time period configured as ameasurement gap.

Table 8 describes a DRX operation of a UE (in the RRC_CONNECTED state).Referring to Table 8, DRX configuration information is received byhigher-layer signaling (e.g., RRC signaling), and DRX ON/OFF iscontrolled by a DRX command from the MAC layer. Once DRX is configured,the UE may perform PDCCH monitoring discontinuously in performing theafore-described/proposed procedures and/or methods, as illustrated inFIG. 5.

Table 8 Type of signals UE procedure 1 ^(st) step RRC signalling(MAC-Receive DRX configuration CellGroupConfig) information 2 ^(nd) Step MACCE((Long) DRX Receive DRX command command MAC CE) 3 ^(rd) Step — Monitora PDCCH during an on-duration of a DRX cycle

MAC-CellGroupConfig includes configuration information required toconfigure MAC parameters for a cell group. MAC-CellGroupConfig may alsoinclude DRX configuration information. For example, MAC-CellGroupConfigmay include the following information in defining DRX.

-   -   Value of drx-OnDurationTimer: defines the duration of the        starting period of the DRX cycle.    -   Value of drx-InactivityTimer: defines the duration of a time        period during which the UE is awake after a PDCCH occasion in        which a PDCCH indicating initial UL or DL data has been detected    -   Value of drx-HARQ-RTT-TimerDL: defines the duration of a maximum        time period until a DL retransmission is received after        reception of a DL initial transmission.    -   Value of drx-HARQ-RTT-TimerDL: defines the duration of a maximum        time period until a grant for a UL retransmission is received        after reception of a grant for a UL initial transmission.    -   drx-LongCycleStartOffset: defines the duration and starting time        of a DRX cycle.    -   drx-ShortCycle (optional): defines the duration of a short DRX        cycle.

When any of drx-OnDurationTimer, drx-InactivityTimer,drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerDL is running, the UEperforms PDCCH monitoring in each PDCCH occasion, staying in the awakestate.

What is claimed is:
 1. A method of receiving a signal by a userequipment (UE) in a wireless communication system, the methodcomprising: receiving one or more physical downlink control channels(PDCCHs) each carrying downlink control information (DCI) including afield indicating a transmitting configuration index (TCI) state; andreceiving, based the one or more PDCCHs, one or more of a plurality ofphysical downlink shared channels (PDSCHs), wherein the plurality ofPDSCHs are configured to carry a same transport block (TB) in aplurality of TCI states, respectively, and wherein the UE determines,for each TCI state, whether a hybrid automatic repeat request (HARQ)operation is enabled or disabled, and transmits HARQ-acknowledgement(ACK) information for the same TB through a physical uplink controlchannel (PUCCH) associated with an HARQ operation-enabled TCI state. 2.The method according to claim 1, wherein the plurality of PDSCHs arerelated to different TCI states, respectively.
 3. The method accordingto claim 1, wherein each DCI of each PDCCH includes informationindicating whether the HARQ operation is enabled or disabled for acorresponding TCI state.
 4. The method according to claim 1, wherein aPUCCH transmit power control (TPC) command is not included incorresponding DCI which disables the HARQ operation for a correspondingTCI state.
 5. The method according to claim 4, wherein the UE obtainsthe PUCCH TPC command only from HARQ operation enabling-DCI.
 6. Themethod according to claim 1, wherein the DCI in each PDCCH scheduleseach PDSCH.
 7. The method according to claim 1, wherein a resource ofthe PUCCH is indicated by corresponding DCI associated with the HARQoperation-enabled TCI state.
 8. The method according to claim 1, whereinthe one or more PDSCHs received by the UE are selected from among theplurality of the PDSCHs, based on each reference signal measurementperformed for each TCI state.
 9. The method according to claim 1,wherein the UE performs one or more PUCCH transmissions related to thesame TB reception, based on each reference signal measurement performedfor each TCI state.
 10. The method according to claim 1, wherein thesame TB carried by the plurality of the PDSCHs is related to a multicastbroadcast service (MBS).
 11. The method according to claim 10, whereinthe DCI is common for a group of UEs receiving the MBS.
 12. Anon-transitory computer readable medium recorded thereon program codesfor performing the method according to claim
 1. 13. A device forwireless communication, the device comprising: a memory configured tostore instructions; and a processor configured to perform operations byexecuting the instructions, the operations comprising: receiving one ormore physical downlink control channels (PDCCHs) each carrying downlinkcontrol information (DCI) including a field indicating a transmittingconfiguration index (TCI) state; and receiving, based the one or morePDCCHs, one or more of a plurality of physical downlink shared channels(PDSCHs), wherein the plurality of PDSCHs are configured to carry a sametransport block (TB) in a plurality of TCI states, respectively, andwherein the UE determines, for each TCI state, whether a hybridautomatic repeat request (HARQ) operation is enabled or disabled, andtransmits HARQ-acknowledgement (ACK) information for the same TB througha physical uplink control channel (PUCCH) associated with an HARQoperation-enabled TCI state.
 14. The device according to claim 13,further comprising; a transceiver configured to transmit or receive asignal under control of the processor.
 15. The device according to claim14, wherein the device is a user equipment (UE) configured to perform3rd generation partnership project (3GPP)-based wireless communication.